• Biomolecules & Therapeutics
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• 제29권3호
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• pp.303-310
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• 2021

In the present study, kaempferol, a flavonoidal natural compound found in Polygonati Rhizoma, was investigated for its potential effect on the gene expression and production of airway MUC5AC mucin. A human respiratory epithelial NCI-H292 cells was pretreated with kaempferol for 30 min and stimulated with epidermal growth factor (EGF) or phorbol 12-myristate 13-acetate (PMA), for the following 24 h. The effect on PMA-induced nuclear factor kappa B (NF-κB) signaling pathway or EGF-induced mitogen-activated protein kinase (MAPK) signaling pathway was investigated. Kaempferol suppressed the production and gene expression of MUC5AC mucins, induced by PMA through the inhibition of degradation of inhibitory kappa Bα (IκBα), and NF-κB p65 nuclear translocation. Also, kaempferol inhibited EGF-induced gene expression and production of MUC5AC mucin through regulating the phosphorylation of EGFR, phosphorylation of p38 MAPK and extracellular signal-regulated kinase (ERK) 1/2 (p44/42), and the nuclear expression of specificity protein-1 (Sp1). These results suggest kaempferol regulates the gene expression and production of mucin through regulation of NF-κB and MAPK signaling pathways, in human airway epithelial cells.

• International Journal of Oral Biology
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• 제37권3호
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• pp.130-136
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• 2012

The GroEL heat-shock protein from Fusobacterium nucleatum, a periodontopathogen, activates risk factors for atherosclerosis in human microvascular endothelial cells (HMEC-1) and ApoE-/- mice. In this study, we analyzed the signaling pathways by which F. nucleatum GroEL induces the proinflammatory factors in HMEC-1 cells known to be risk factors associated with the development of atherosclerosis and identified the cellular receptor used by GroEL. The MAPK and NF-${\kappa}B$ signaling pathways were found to be activated by GroEL to induce the expression of interleukin-8 (IL-8), monocyte chemoattractant protein 1 (MCP-1), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin, and tissue factor (TF). These effects were inhibited by a TLR4 knockdown. Our results thus indicate that TLR4 is a key receptor that mediates the interaction of F. nucleatum GroEL with HMEC-1 cells and subsequently induces an inflammatory response via the MAPK and NF-${\kappa}B$ pathways.

• The Korean Journal of Physiology and Pharmacology
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• 제19권3호
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• pp.263-268
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• 2015

5-Lipoxygenase (5-LO) plays a pivotal role in the progression of atherosclerosis. Therefore, this study investigated the molecular mechanisms involved in 5-LO expression on monocytes induced by LPS. Stimulation of THP-1 monocytes with LPS ($0{\sim}3{\mu}g/ml$) increased 5-LO promoter activity and 5-LO protein expression in a concentration-dependent manner. LPS-induced 5-LO expression was blocked by pharmacological inhibition of the Akt pathway, but not by inhibitors of MAPK pathways including the ERK, JNK, and p38 MAPK pathways. In line with these results, LPS increased the phosphorylation of Akt, suggesting a role for the Akt pathway in LPS-induced 5-LO expression. In a promoter activity assay conducted to identify transcription factors, both Sp1 and NF-${\kappa}B$ were found to play central roles in 5-LO expression in LPS-treated monocytes. The LPS-enhanced activities of Sp1 and NF-${\kappa}B$ were attenuated by an Akt inhibitor. Moreover, the LPS-enhanced phosphorylation of Akt was significantly attenuated in cells pretreated with an anti-TLR4 antibody. Taken together, 5-LO expression in LPS-stimulated monocytes is regulated at the transcriptional level via TLR4/Akt-mediated activations of Sp1 and NF-${\kappa}B$ pathways in monocytes.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.2909-2914
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• 2015

Objective: To investigate the protective effect of quercetin on radiation induced lung injury (RILI) and related mechanisms. Materials and Methods: Mice treated with radiation and/or quercetin were sacrificed at 1-8 weeks after irradiation under anesthesia. Lung tissues were collected for histological examination. Immunohistochemistry (IHC) and Western blotting were performed to detect the protein expression of nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) and Mitogen-activated protein kinases (MAPK) pathway. Results: Hematoxylin and eosin (HE) staining showed that radiation controls displayed more severe lung damage than quercetin groups, either high or low dose. Results of IHC and Western blotting demonstrated the expression level of $NF-{\kappa}B$ to be decreased and that of an inhibitor of $NF-{\kappa}B$ ($I{\kappa}b-{\alpha}$) to be increased by the quercetin intervention compared with the radiation control group. Numbers of JNK/SAPK, p38 and p44/p42 positive inflammatory cells were decreased in the radiation+quercetin injection group (P<0.05). Conclusions: Quercetin may play a radio-protective role in mice lung via suppression of $NF-{\kappa}B$ and MAPK pathways.

• Journal of Ginseng Research
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• 제42권1호
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• pp.50-56
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• 2018

Background: Saponins from Panax japonicus (SPJ) are the most abundant and main active components of P. japonicus, which replaces ginseng roots in treatment for many kinds of diseases in the minority ethnic group in China. Our previous studies have demonstrated that SPJ has the effects of anti-inflammation through the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-${\kappa}B$) signaling pathways. The present study was designed to investigate whether SPJ can modulate intestinal tight junction barrier in aging rats and further to explore the potential mechanism. Methods: Aging rats had been treated with different doses (10 mg/kg, 30 mg/kg, and 60 mg/kg) of SPJ for 6 mo since they were 18 mo old. After the rats were euthanized, the colonic samples were harvested. Levels of tight junctions (claudin-1 and occludin) were determined by immunohistochemical staining. Levels of proinflammatory cytokines (interleukin-$1{\beta}$ and tumor necrosis factor-${\alpha}$) were examined by Western blot. NF-${\kappa}B$ and phosphorylation of MAPK signaling pathways were also determined by Western blot. Results: We found that SPJ increased the expression of the tight junction proteins claudin-1 and occludin in the colon of aging rats. Treatment with SPJ decreased the levels of interleukin-$1{\beta}$ and tumor necrosis factor-${\alpha}$, reduced the phosphorylation of three MAPK isoforms, and inhibited the expression of NF-${\kappa}B$ in the colon of aging rats. Conclusion: The studies demonstrated that SPJ modulates the damage of intestinal epithelial tight junction in aging rats, inhibits inflammation, and downregulates the phosphorylation of the MAPK and $NF-{\kappa}B$ signaling pathways.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.190-198
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• 2018

Periodontitis is an inflammatory disease caused by microbial lipopolysaccharide (LPS), destroying gingival tissues and alveolar bone in the periodontium. In the present study, we evaluated the anti-inflammatory and anti-osteoclastic effects of panduratin A, a chalcone compound isolated from Boesenbergia pandurata, in human gingival fibroblast-1 (HGF-1) and RAW 264.7 cells. Treatment of panduratin A to LPS-stimulated HGF-1 significantly reduced the expression of interleukin-$1{\beta}$ and nuclear factor-kappa B (NF-${\kappa}B$), subsequently leading to the inhibition of matrix metalloproteinase-2 (MMP-2) and MMP-8 compared with that in the LPS control ($^{**}p$ < 0.01). These anti-inflammatory responses were mediated by suppressing the mitogen-activated protein kinase (MAPK) signaling and activator protein-1 complex formation pathways. Moreover, receptor activator of NF-${\kappa}B$ ligand (RANKL)-stimulated RAW 264.7 cells treated with panduratin A showed significant inhibition of osteoclastic transcription factors such as nuclear factor of activated T-cells c1 and c-Fos as well as osteoclastic enzymes such as tartrate-resistant acid phosphatase and cathepsin K compared with those in the RANKL control ($^{**}p$ < 0.01). Similar to HGF-1, panduratin A suppressed osteoclastogenesis by controlling MAPK signaling pathways. Taken together, these results suggest that panduratin A could be a potential candidate for development as a natural anti-periodontitis agent.

• Natural Product Sciences
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• 제24권1호
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• pp.28-35
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• 2018

Pulegone is a naturally occurring organic compound obtained from essential oils from a variety of plants. The aim of this study was to investigate the anti-inflammatory effects through the inhibitory mechanism of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), nuclear factor kappa B ($NF-{\kappa}B$), mitogen-activated protein kinases (MAPK) pathways and the activation of nuclear factor erythroid 2-related factor 2 (Nrf2)/ heme oxygenase (HO)-1 pathways in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Results revealed that pulegone significantly inhibited NO production as well as iNOS and COX-2 expressions. Meanwhile, western blot analysis showed that pulegone down-regulated LPS-induced $NF-{\kappa}B$ and MAPKs activation in RAW 264.7 cells. Furthermore, the selected compound suppressed LPS-induced intracellular ROS production in RAW 264.7 cells, while the expression of stress response gene, HO-1, and its transcriptional activator, Nrf-2 was upregulated upon pulegone treatment. Taking together, these findings provided that pulegone inhibited the LPS-induced expression of inflammatory mediators via the down-regulation iNOS, COX-2, $NF-{\kappa}B$, and MAPKs signaling pathways as well as up-regulation of Nrf-2/HO-1 indicating that pulegone has a potential therapeutic and preventive application in various inflammatory diseases.

• Journal of Ginseng Research
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• 제43권1호
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• pp.95-104
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• 2019

Background: Oxidized low-density lipoprotein (ox-LDL) causes vascular endothelial cell inflammatory response and apoptosis and plays an important role in the development and progression of atherosclerosis. Ginsenoside compound K (CK), a metabolite produced by the hydrolysis of ginsenoside Rb1, possesses strong anti-inflammatory effects. However, whether or not CK protects ox-LDL-damaged endothelial cells and the potential mechanisms have not been elucidated. Methods: In our study, cell viability was tested using a 3-(4, 5-dimethylthiazol-2yl-)-2,5-diphenyl tetrazolium bromide (MTT) assay. Expression levels of interleukin-6, monocyte chemoattractant protein-1, tumor necrosis factor-${\alpha}$, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 were determined by enzyme-linked immunosorbent assay and Western blotting. Mitochondrial membrane potential (${\Delta}{\Psi}m$) was detected using JC-1. The cell apoptotic percentage was measured by the Annexin V/ propidium iodide (PI) assay, lactate dehydrogenase, and caspase-3 expression. Apoptosis-related proteins, nuclear factor $(NF)-{\kappa}B$, and mitogen-activated protein kinases (MAPK) signaling pathways protein expression were quantified by Western blotting. Results: Our results demonstrated that CK could ameliorate ox-LDL-induced human umbilical vein endothelial cells (HUVECs) inflammation and apoptosis, $NF-{\kappa}B$ nuclear translocation, and the phosphorylation of p38 and c-Jun N-terminal kinase (JNK). Moreover, anisomycin, an activator of p38 and JNK, significantly abolished the anti-apoptotic effects of CK. Conclusion: These results demonstrate that CK prevents ox-LDL-induced HUVECs inflammation and apoptosis through inhibiting the $NF-{\kappa}B$, p38, and JNK MAPK signaling pathways. Thus, CK is a candidate drug for atherosclerosis treatment.

• BMB Reports
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• 제42권3호
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• pp.148-153
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• 2009

Pyrrolidine dithiocarbamate (PDTC) is a stable anti-oxidant or pro-oxidant, depending on the situation, and it is widely used to inhibit the activation of NF-${\kappa}B$. We recently reported that PDTC activates the MIP-2 gene in a NF-${\kappa}B$-independent and c-Jun-dependent manner in macrophage cells. In this work, we found that PDTC activates signal transduction pathways in mouse ES cells. Among the three different mitogen-activated protein kinase (MAPK) pathways, including the extracellular-signal-regulated kinase (ERK), p38 MAP kinase, and stress-activated protein kinase (SAPK)/Jun N-terminal kinase (JNK) pathways, only the ERK pathway was significantly activated in mouse ES cells after stimulation with PDTC. Additionally, we observed a synergistic activation of ERK and induction of c-Fos after stimulation with PDTC in the presence of mouse embryonic fibroblast (MEF) conditioned medium. In contrast, another NF-${\kappa}B$ inhibitor, BMS-345541, did not activate the MAP kinase pathways or induce expression of c-Fos. These results suggest that changes in the presence of the NF-${\kappa}B$ inhibitor PDTC should be carefully considered when it used with mouse ES cells.

• Journal of Nutrition and Health
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• 제49권4호
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• pp.241-246
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• 2016

Purpose: Aloe-emodin (AE), an ingredient of aloe, is known to exhibit anti-inflammatory activities. However, little is known about the underlying molecular mechanisms of its inflammatory modulatory activity in vitro. In the present study, we investigated the anti-inflammatory potential of AE using $Pam_3CSK_4$-stimulated macrophages. Methods: RAW 264.7 macrophages were treated with AE (0~20 mM) for 1 h, followed by treatment with $Pam_3CSK_4$ for 1 h. After incubation, mRNA expression levels of cytokines were measured. The effect of AE on TLR2-related molecules was also investigated in $Pam_3CSK_4$-stimulated RAW 264.7 macrophages. Results: AE attenuated $Pam_3CSK_4$-stimulated expression of proinflammatory cytokines, including tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and interleukin-$1{\beta}$ ($IL-1{\beta}$) in RAW 264.7 macrophages. Two concentrations of AE ($10{\mu}M$ and $20{\mu}M$) effectively reduced mRNA expression of TLR2 by 41.18% and 54.43%, respectively, compared to that in control cells (p < 0.05). AE also decreased nuclear factor-kappa B ($NF-{\kappa}B$) activation and mitogen-activated protein kinase (MAPK) phosphorylation. Phosphorylation levels of ERK1/2, p38, and JNK were markedly reduced by $20{\mu}M$ AE. In particular, AE decreased phosphorylation of ERK in a dose-dependent manner in $Pam_3CSK_4$-stimulated RAW 264.7 macrophages. Conclusion: Our data indicate that AE exerts its anti-inflammatory effect by suppressing TLR2-mediated activation of $NF-{\kappa}B$ and MAPK signaling pathways in macrophages.